LYME DISEASE

Lyme Disease

Lyme Disease

Lyme disease is a multistage, multisystem infection caused by small bacteria called spirochetes (Borrelia burgdorferi) that are transmitted by Ixodes ticks. This species of tick, also called the deer tick, is much smaller than the type of tick usually found on dogs—it is only about size of a poppy seed—and thrives on wildlife such as the white-tailed deer that live in grassy, woody, brushy, or marshy regions. These ticks can also survive on domestic animals, including dogs, cats, and horses.

History

Lyme disease was first identified in Old Lyme, Connecticut, in 1975 (though it may have been recognized earlier in Europe). Over 103,000 cases were reported to the Centers for Disease Control (CDC) between 1982 and 1997 alone, with about 16,000 new cases reported each year. Long-term consequences and optimal treatment are still being explored, but we already know that this disease is usually amenable to antibiotic therapy if treated early. Without effective treatment, however, Lyme disease can lead to serious and possibly recurring disorders of the joints, nerves, and heart. (Allen 2003)

Etiology

The infected tick injects its spirochete-laden saliva into the bloodstream, where they incubate for 3 to 32 days and then migrate to the skin, causing the characteristic erythema migrans (EM) rash.

Vulnerable People

While people of all ages can be infected with Lyme disease, the highest reported rates occur in people under 15 and between 30 and 59 years of age. Cases have been reported in 48 states, as well as the District of Columbia, but the disease is most often contracted in the northeastern, north central, and Pacific coastal regions of the United States—areas in which the B. burgdorferi spirochete is endemic. Lyme disease has also been reported in Europe, Japan, China, and Russia. Residents and visitors to endemic areas are at risk. The spirochete can be transmitted year-round, but most cases are contracted between April and July. (Jerigan 1999)

Symptoms

A bull's-eye or circular red ring or rash, which develops around the tick bite after about 3 to 10 days, often signals Lyme disease, although many women never develop a rash. This ring can grow to 5 inches or more in diameter. Other early symptoms (stage 1 of the disease) may include flulike symptoms such as mild fever, headache, fatigue, listlessness, muscle and joint pains, and swollen glands.

Over the next 3 to 4 weeks, the rash gradually fades, with or without treatment. During this time (stage ...